In FIG. 31 of Patent Literature 1, a spring operation device for use in a switchgear is depicted in which the device includes two springs: an opening coil spring and a closing coil spring. In this conventional spring operation device, when the biased closing coil spring is released during a closing operation, a switch-on lever rotates about a main shaft under a condition where a guide engages with a first tripping latch, the first tripping latch engages with a tripping trigger, and the tripping trigger engages with a lock plate. In response to this rotation, a four-joint link (a first link, a second link, and a second blocking lever) rotates about the main shaft, while being supported by the guide. Further, a first blocking lever rotates about the main shaft and then compresses and biases the opening spring so as to close the breaker.
In the spring operation device described in Patent Literature 1 mentioned above, a first lock member and the lock plate are provided, and the lock plate locks the tripping trigger during a closing operation. Consequently, even when an opening command is improperly input and a tripping electromagnet is thus energized, the tripping trigger is configured so as not to rotate and perform an opening operation. The lock plate is configured so as to be pushed out by the first lock member and to disengage from the tripping trigger when the closing operation has been completed. Therefore, the spring operation device is in a state where it is capable of performing an opening operation.
In the spring operation device described in Patent Literature 2, a switch-on stopping device is provided, as illustrated in FIG. 3 of the Patent Literature, in order to prevent a closing operation from being performed immediately after an opening operation. Engagement of a trigger lever with a switch-on trigger is controlled by using an interlocking electromagnet. In this conventional spring operation device, even when a switch-on electromagnet is energized during an opening operation, the switch-on trigger is not driven and therefore a switch-on operation is prevented from being performed.